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More on David Cook's Brother, Illness

As impressive as David Cook has been on American Idol, the fact that he's been able to perform at such a high level is even more amazing given the sad state of a family member:

David's older brother Adam Cook is battling cancer. The American Idol finalist hasn't spoken about the illness, out of respect for his brother. He also didn't want to sympathy votes.

Cook isn't the first Idol to compete while dealing with a personal crisis, as People Magazinereports.

"The week before we came up for the Top 24, my best friend passed away, and I was just like, 'I don't know if I can go out there,'" last year's champ Jordin Sparks said. "I went to the funeral and came back and then my uncle passed away â€" and then my grandma ... and so I had three deaths go on during the show.

"It's hard because you have to go out there and put this smile on your face," she added. "It's very exhausting, and it's very overwhelming and kind of gets to you. I mean I got sick a couple times, just because I was so tired and kept trying to do all this stuff and it was crazy."